The BIGGEST improvement, is not necessarily the editor. It's that there's an established knowledge base from both 1's editor and Larian's commitment to being more involved in the mod community. In the early D:OS 1 editor days everyone was running around like chickens with their heads cut off. Now you'll have help and answers. I'll try to help out as well as I did on 1's mod board :P
The main thing I'd say about the D:OS 2 editor is to the people looking for a more simplified experience, that's not really there. It is in some aspects but not enough that I'd call the editor substantially less complex. Wind sort of explained that.
It is somewhat easier to just dive in and get some things going. Scripts are included where in the original 1 editor they were not. In 2's editor you can rip off a few level templates place some characters and make things happen in about an hour.
